Orbits for eighteen visual binaries and two double-line spectroscopic binaries observed with hrcam on the CTIO SOAR 4m telescope, using a new bayesian orbit code based on markov chain Monte Carlo
Author
dc.contributor.author
Méndez Bussard, René Alejandro
Author
dc.contributor.author
Claveria, Ruben M.
Author
dc.contributor.author
Orchard Concha, Marcos
Author
dc.contributor.author
Silva, Jorge F.
Admission date
dc.date.accessioned
2018-06-08T19:29:55Z
Available date
dc.date.available
2018-06-08T19:29:55Z
Publication date
dc.date.issued
2017
Cita de ítem
dc.identifier.citation
Astronomical Journal Vol.154 (5): 187
es_ES
Identifier
dc.identifier.other
10.3847/1538-3881/aa8d6f
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/148742
Abstract
dc.description.abstract
We present orbital elements and mass sums for 18 visual binary stars of spectral types B to K (five of which are new orbits) with periods ranging from 20 to more than 500 yr. For two double-line spectroscopic binaries with no previous orbits, the individual component masses, using combined astrometric and radial velocity data, have a formal uncertainty of similar to 0.1 M-circle dot. Adopting published photometry and trigonometric parallaxes, plus our own measurements, we place these objects on an H-R diagram and discuss their evolutionary status. These objects are part of a survey to characterize the binary population of stars in the Southern Hemisphere using the SOAR 4 m telescope+HRCAM at CTIO. Orbital elements are computed using a newly developed Markov chain Monte Carlo (MCMC) algorithm that delivers maximum-likelihood estimates of the parameters, as well as posterior probability density functions that allow us to evaluate the uncertainty of our derived parameters in a robust way. For spectroscopic binaries, using our approach, it is possible to derive a self-consistent parallax for the system from the combined astrometric and radial velocity data ("orbital parallax"), which compares well with the trigonometric parallaxes. We also present a mathematical formalism that allows a dimensionality reduction of the feature space from seven to three search parameters (or from 10 to seven dimensionsincluding parallaxin the case of spectroscopic binaries with astrometric data), which makes it possible to explore a smaller number of parameters in each case, improving the computational efficiency of our MCMC code.
es_ES
Patrocinador
dc.description.sponsorship
Chilean Centro de Excelencia en Astrofisica y Tecnologias Afines (CATA) BASAL
PFB/06
Millennium Institute of Astrophysics (MAS) of the Iniciativa Cientifica Milenio del Ministerio de Economia, Fomento y Turismo de Chile
IC120009
CONICYT/FONDECYT
1151213
1170044
1170854
CONICYT, Chile
CONICYT-PCHA/MagisterNacional/2016-22162232
Advanced Center for Electrical and Electronic Engineering
FB0008
CONICYT
PIA ACT1405
Basal Project
FB0008
CN2014B-27
CN2015B-6
CN2016A-4
Orbits for eighteen visual binaries and two double-line spectroscopic binaries observed with hrcam on the CTIO SOAR 4m telescope, using a new bayesian orbit code based on markov chain Monte Carlo